It was in response to the interview with DC Police Chief Cathy Lanier by 60 Minutes. In the interview which dealt with active shooters, Lanier said that it was unreasonable to expect the police to arrive in time to stop most mass shootings. She told Anderson Cooper:

I always say if you can get out, getting out's your first option, your best option. If you're in a position to try and take the gunman down, to take the gunman out, it's the best option for saving lives before police can get there. And that's-- you know, that's kind of counterintuitive to what cops always tell people, right? We always tell people, "Don't-- you know, don't take action. Call 911. Don't intervene in the robbery"-- you know-- you know-- we've never told people, "Take action." It's a different-- this is a different scenario.

You can see the full interview below which also includes comments by NYC Police Commissioner William Bratton.